As some you know, I just put my 92 965 Turbo together and I want some extra boost, I don't really plan on tracking the car , but maybe an autocross or a few seconds on full on the road, The only mod I have is a FabSpeed Cat bypass. and thinking of a wastegate bypass in the future.

My old 76 911 GT clone 423HP 3.3 Turbo car had tial wastegate with 1.1 bar boost , and it ran a lot lean on top, It lasted for 15 years and countless track events and autocrosses and weekly drag racing.

These 964 Turbo are limited .7 bar, it seems to want more boost. Most people change the wastegate springs to up the boost, Why not a boost controller ? wouldn't a boost controller give more tuneability ?

What springs are most common to use on these cars ? Can I run 1.1 bar boost safely?

I have a GrimmSpeed Manual boost controller in the engine bay (so I don't turn up the boost when the adrenaline is flowing) and I think it works well. It is very consistent as measured with my PLX boost gauge and has increments of .25 psi, so you put it right where you want it. I had a 1.0 bar spring in my TiAl but I found it was not consistent enough for me and this is a better solution, IMO. I have a .7 bar spring in the wastegate.

I am set at 1.0 bar and happy with the performance, so will not set it higher. I doubt 1.1 is an engine killer, but I'm not risking it.

I have a GrimmSpeed Manual boost controller in the engine bay (so I don't turn up the boost when the adrenaline is flowing) and I think it works well. It is very consistent as measured with my PLX boost gauge and has increments of .25 psi, so you put it right where you want it. I had a 1.0 bar spring in my TiAl but I found it was not consistent enough for me and this is a better solution, IMO. I have a .7 bar spring in the wastegate.

I am set at 1.0 bar and happy with the performance, so will not set it higher. I doubt 1.1 is an engine killer, but I'm not risking it.

Jeff how many clicks did you do ? 18 clicks at .25 psi each click = .3013 bar + .7 bar =1.013 bar which = 14.7 total PSI ? does that sound right to you ? see diagram below, is this the way you installed the boost controller on your car ?

Jeff how many clicks did you do ? 18 clicks at .25 psi each click = .3013 bar + .7 bar =1.013 bar which = 14.7 total PSI ? does that sound right to you ? see diagram below, is this the way you installed the boost controller on your car ?

Is there an advantage to this hookup? ^^^ My hose goes from the intercooler (source) directly to the manual controller in the console and back to the lower port on the wg. The top port vented to atmosphere.

Jeff how many clicks did you do ? 18 clicks at .25 psi each click = .3013 bar + .7 bar =1.013 bar which = 14.7 total PSI ? does that sound right to you ? see diagram below, is this the way you installed the boost controller on your car ?

Quote:

Originally Posted by Hot Euro

Is there an advantage to this hookup? ^^^ My hose goes from the intercooler (source) directly to the manual controller in the console and back to the lower port on the wg. The top port vented to atmosphere.

I plumbed mine like Hot Euro did. It's simpler and it works.

I don't remember exactly how I setup the Grimmspeed out of the box, but I do know I was WAY OFF. On my first boost, the overboost relay cut out the fuel and saved me. I dialed it way back, and then did a bunch of runs where I slowly increased it and dialed it in while using the PLX to see actual boost pressure. Once I got it to where I wanted it, I haven't touched it since.

Get an AFR gauge first. Then get a quality EBC with overboost protection.

That first picture is a little confusing - you would plumb it like that if you are running an ebc, not a manual controller. In a manual setup you need to vent diaphragm pressure to atmosphere somewhere, with a EBC that vent pressure is modulated via the solenoid to control onset pressure.

I would get an AFR meter 1st. - make sure your AFR is safe with a healthy margin because of number 2 below

2nd the boost was so low on the 964 turbo due to terrible timing resolution - 3 teeth on the flywheel
and they are not symmetrical. Put a timing light on it under boost and see it jump around.

Mine ran dangerously lean with a 1 bar spring with stock internals - after headers and free flow muffler (rarlyl8) it was way too lean. I then needed rarlyl8 to modify my WUR.

Black Hat is correct about the AFR's. Going from .7 to 1.0 dramatically changes the AFR under boost. I already had the Leask WUR, so I definitely was tweaking WCP, boost enrichment and boost onset to get the AFR curve correct.
But again, once I got it right, I'm not playing with it anymore...

If you don't have a good boost/AFR gauge, don't up the boost until you do, IMO.

My car is a 965 3.3, I just went for a test drive and checked am AFR's as a base, 2nd gear pull 10.2 afr, shifting to 3rd to 6000 rpm's 10.9 to 11.2, A little rich, and I have no cat,

I raised the idle to 1000 prm's to make for the drop when I turn the AC, saying that, It idles at 17.9 afr happily. my 930 3.3 idled at 13.5 to 14 afr. hnnn...... I feel that when I install the Manual Boost controller it should take care of the rich on boost, I dont to play with WUR or the SP, because runs perfect now, just rich on boost

Any ideas on a boost gauge that I can install temporarily for testing purposes ? Can I use the stock boost sending unit for a electronic gauge or would it be better to hook a Vacuum style boost gauge ? I could hook it up to a vacuum line somewhere? and which vacuum hose can I tap into? again for only testing and setup only.

I was thinking of Teeing off the same vacuum line before the controller for the boost gauge ? what do you think ?